Gustav Sandin

Life cycle assessment of construction materials: the influence of assumptions in end-of-life modelling

PurposeThe nature of end-of-life (EoL) processes is highly uncertain for constructions built today. This uncertainty is often neglected in life cycle assessments (LCAs) of construction materials. This paper tests how EoL assumptions influence LCA comparisons of two alternative roof construction elements: glue-laminated wooden beams and steel frames. The assumptions tested include the type of technology and the use of attributional or consequential modelling approaches.MethodsThe study covers impact categories often considered in the construction industry: total and non-renewable primary energy demand, water depletion, global warming, eutrophication and photo-chemical oxidant creation. The following elements of the EoL processes are tested: energy source used in demolition, fuel type used for transportation to the disposal site, means of disposal and method for handling allocation problems of the EoL modelling. Two assumptions regarding technology development are tested: no development from today’s technologies and that today’s low-impact technologies have become representative for the average future technologies. For allocating environmental impacts of the waste handling to by-products (heat or recycled material), an attributional cut-off approach is compared with a consequential substitution approach. A scenario excluding all EoL processes is also considered.Results and discussionIn all comparable scenarios, glulam beams have clear environmental benefits compared to steel frames, except for in a scenario in which steel frames are recycled and today’s average steel production is substituted, in which impacts are similar. The choice of methodological approach (attributional, consequential or fully disregarding EoL processes) does not seem to influence the relative performance of the compared construction elements. In absolute terms, four factors are shown to be critical for the results: whether EoL phases are considered at all, whether recycling or incineration is assumed in the disposal of glulam beams, whether a consequential or attributional approach is used in modelling the disposal processes and whether today’s average technology or a low-impact technology is assumed for the substituted technology.ConclusionsThe results suggest that EoL assumptions can be highly important for LCA comparisons of construction materials, particularly in absolute terms. Therefore, we recommend that EoL uncertainties are taken into consideration in any LCA of long-lived products. For the studied product type, LCA practitioners should particularly consider EoL assumptions regarding the means of disposal, the expected technology development of disposal processes and any substituted technology and the choice between attributional and consequential approaches.

Using the planetary boundaries framework for setting impact-reduction targets in LCA contexts

PurposeThe planetary boundaries (PBs) framework suggests global limits for environmental interventions which could be used to set global goals for reducing environmental impacts. This paper proposes a procedure for using such global goals for setting impact-reduction targets at the scale of products for use, for example, in life cycle assessment (LCA) contexts, e.g. as a basis for evaluating the potential of interventions to reduce the environmental impact of products.MethodsThe procedure consists of four steps: (i) identifying the PBs quantified in literature that correspond to an impact category which is studied in the product assessment context in question; (ii) interpreting what the identified PBs imply in terms of global impact-reduction targets; (iii) translating the outcome of (ii) to reduction targets for the particular global market segment to which the studied product belongs; and (iv) translating the outcome of (iii) to reduction targets for the studied product. The procedure requires some assumptions and value-based choices—the influence of these is tested by applying the procedure in a specific LCA context: a study of Swedish clothing consumption.Results and discussionThe application of the procedure in an LCA context suggested the need for eliminating all or nearly all impact of Swedish clothing consumption for most impact categories. Thus, it is improbable that a single type of impact-reduction intervention (e.g. technological development or changed user behaviour) is sufficient. The outcome’s strong dependence on impact category suggests that the procedure can help in prioritising among impact categories. Furthermore, the outcome exhibited a strong dependence on the chosen method for allocating the globally allowed impact between regions—this was tested by applying different principles identified in a literature review on the allocation of emissions rights. The outcome also strongly depended on the geographical scope—this was tested by changing the geographical scope from Sweden to Nigeria.ConclusionsThe proposed procedure is feasible to use for LCA practitioners and other environmental analysts, and data is available to apply the procedure in contexts with different geographical scopes. Value-based choices are, however, unavoidable and significantly influence the outcome, which accentuates the subjectivity and potentially controversial nature of allocating a finite impact space to certain regions, market segments and products. How to match PBs with appropriate LCA impact categories is an important area for future research.

Will clothing be sustainable? Clarifying sustainable fashion

The Mistra Future Fashion research programme (2011–2019) is a large Swedish investment aimed at reducing the environmental impact of clothing consumption. Midway into the programme, research results and insights were reviewed with the intent to see what picture appears from this interdisciplinary consortium, developed to address the multiple sustainability challenges in clothing consumption and the tools for intervention. Such tools comprise product design, consumer behaviour changes, policy development, business models, technical development, recycling, life cycle assessment (LCA) and social life cycle assessment (SLCA). This chapter quantifies the extent of the sustainability challenge for the apparel sector, via an analysis of five garment archetypes. It also considers to what extent different interventions for impact reduction can contribute in society’s endeavour towards sustainability, in terms of staying within an “environmentally safe and socially just operating space”, inspired by the planetary boundaries approach. In particular, the results show whether commonly proposed interventions are sufficient or not in relation to the impact reduction necessary according to the planetary boundaries. Also, the results clarify which sustainability aspects that the clothing industry are likely to manage sufficiently if the proposed interventions are realised and which sustainability aspects that will require more radical interventions in order to reach the targets.

LCA of Forest Products—Challenges and Solutions

This chapter provides an extensive walkthrough of the important challenges encountered when carrying out life cycle assessment (LCA) of forest products, and proposes some solutions to these challenges, with examples from the scientific literature and technical reports. The topics include: modelling future and/or uncertain product systems, handling multi-functionality (i.e., allocation problems), inventory analysis and impact assessment (carbon flow modelling, assessing climate impact, biodiversity loss, water cycle disturbances and energy use), managing trade-offs and connecting the LCA work to global environmental challenges, and integrating LCA work in the R&D of new products.

Life Cycle Assessment of Forest Products

Reducing environmental degradation and our dependency of finite resources are important motivations for developing a more bio-based society. In such a society, the most abundant renewable resource ...

Environmental assessment of bio-based building materials

Abstract This chapter introduces the environmental assessment methods used to understand the environmental impact of bio-based materials. It highlights the current and future environmental requirement products need to meet in the built environment. Typically, this is based around life cycle assessment (LCA) techniques, and specifically of interest to bio-based products is how stored carbon is accounted for in assessment of the products. It then explains how this fits with models such as the circular economy and the low-carbon economy as the construction industry tackles its substantial contribution to climate change. The final section of the chapter highlights the measurement and certification schemes that exist including eco-labels and environmental product declarations and the whole building assessment schemes used internationally.

Future Research Needs

This chapter summarises future research needs related to improving the methods and practices of life cycle assessment (LCA) of forest products. Among others, the research needs concern scenario modelling, attributional and consequential modelling, end-of-life modelling, impact assessment (of climate change, biodiversity loss, and water cycle disturbances), reducing confusion surrounding terminology, and integrating LCA in R&D settings.

Strengths and Weaknesses of Forest Products

This chapter introduces some of the strengths and weaknesses of forest products, for example relating to renewability, biodegradability, climate change, biodiversity loss and water cycle disturbances, indirect land use and land use change. It is explained how the complexities surrounding these topics are key reasons for why environmental assessments are needed to ensure that forest products replacing non-forest products actually reduce environmental impact.

Carbon footprints in the textile industry : Chapter 1

Abstract Climate change is a key environmental challenge of our time. Carbon footprinting is a key environmental accounting tool for business managers, policy makers and non-governmental organisations attempting to identify mitigation measures that reduce the threat of climate change. The textile industry is increasingly engaged in carbon footprinting as a part of policy development and product design. As is the case for any accounting tool, there are a number of methodological issues that need to be handled by analysts producing carbon footprint calculations, and by the consumers of such information, in order to ensure that the information is meaningful in its particular context. This chapter describes these key challenges, the standardisation processes that have arisen to meet them, the outcomes of practical carbon footprint calculations for textile manufacturing facilities and textile products, and recent work on carbon labelling of products. It also attempts to describe current trends and attempts to qualitatively extrapolate future developments in this field.

1 – Carbon footprints in the textile industry

Abstract Climate change is a key environmental challenge of our time. Carbon footprinting is a key environmental accounting tool for business managers, policy makers and non-governmental organisations attempting to identify mitigation measures that reduce the threat of climate change. The textile industry is increasingly engaged in carbon footprinting as a part of policy development and product design. As is the case for any accounting tool, there are a number of methodological issues that need to be handled by analysts producing carbon footprint calculations, and by the consumers of such information, in order to ensure that the information is meaningful in its particular context. This chapter describes these key challenges, the standardisation processes that have arisen to meet them, the outcomes of practical carbon footprint calculations for textile manufacturing facilities and textile products, and recent work on carbon labelling of products. It also attempts to describe current trends and attempts to qualitatively extrapolate future developments in this field.